Semiconductor device and manufacturing method for semiconductor device

ABSTRACT

A semiconductor device includes an insulating layer, conductors, a semiconductor element and a sealing resin. The insulating layer has first and second surfaces opposite to each other in the thickness direction. Each conductor has an embedded part whose portion is embedded in the insulating layer and a redistribution part disposed at the second surface and connected to the embedded part. The semiconductor element has electrodes provided near the first surface and connected the embedded parts of the conductors. The semiconductor element is in contact with the first surface. The sealing resin partially covers the semiconductor element and is in contact with the first surface. The redistribution parts include portions outside the semiconductor element as viewed in the thickness direction. The insulating layer has grooves recessed from the second surface in the thickness direction. The redistribution parts are in contact with the grooves.

TECHNICAL FIELD

The present disclosure relates to a semiconductor device of a Fan-Outtype.

BACKGROUND ART

With recent miniaturization of electronic devices, size reduction ofsemiconductor devices for use in electronic devices is underway. AFan-Out type semiconductor device is known as a device developed undersuch circumstances. This type of semiconductor device includes asemiconductor element having a plurality of electrodes, an insulatinglayer in contact with the semiconductor element, a plurality ofconductors disposed on the insulating layer and connected to theelectrodes, and a sealing resin disposed in contact with the insulatinglayer and covering a portion of the semiconductor element. Theconductors include portions that are located outside the semiconductorelement as viewed in the thickness direction. Such a configuration makesit possible to adapt the semiconductor device to various shapes ofwiring patterns of a wiring board on which the semiconductor device isto be mounted while also achieving the size reduction of thesemiconductor device.

Patent Document 1 discloses an example of a method of manufacturing sucha Fan-Out type semiconductor device. The manufacturing method includesthe steps of embedding a semiconductor element having a plurality ofelectrodes into a sealing resin (a cured member in Patent Document 1),forming an insulating layer (a buffer coat film in Patent Document 1) incontact with both the semiconductor element and the sealing resin, andforming a plurality of conductors connected to the electrodes. The stepof embedding the semiconductor element into the sealing resin isperformed such that the electrodes are exposed from the sealing resin.In the step of forming an insulating layer, a plurality of openings areformed in the insulating layer such that the electrodes are exposed byphotolithography patterning using a mask. In the step of forming theconductors, a plating layer is formed in the openings of the insulatinglayer and on the insulating layer.

In the step of embedding the semiconductor element into the sealingresin, the sealing resin undergoes shrinkage in curing, which causesdisplacement of the semiconductor element. Forming openings in theinsulating layer in this state results in misalignment between theopenings and the electrodes. Forming conductors in such a conditioncauses misalignment between the electrodes and the conductors at thejoint portion. To improve the reliability of the semiconductor device,it is desired to prevent such misalignment.

TECHNICAL REFERENCE Patent Document

-   Patent Document 1: JP-A-2016-89081

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The present disclosure has been proposed under the above-notedcircumstances, and an object of the present disclosure is to provide asemiconductor device capable of preventing misalignment between theelectrodes of a semiconductor element and conductors at the jointportion and a method of manufacturing such a semiconductor device.

Means for Solving the Problems

A semiconductor device provided according to a first aspect of thepresent disclosure comprises: a first insulating layer having a firstsurface and a second surface facing away from each other in a thicknessdirection; a plurality of first conductors each having a first embeddedpart and a first redistribution part, with at least a portion of thefirst embedded part being embedded in the first insulating layer, andwith the first redistribution part being disposed at the second surfaceand connected to the first embedded part; a semiconductor element thatis in contact with the first surface and has a plurality of electrodes,with the electrodes being provided near the first surface and connectedto at least a predetermined number of the first embedded parts of thefirst conductors; and a sealing resin that is in contact with the firstsurface and covers a portion of the semiconductor element. The firstredistribution parts of the first conductors include portions locatedoutside the semiconductor element as viewed in the thickness direction.The first insulating layer has a plurality of first grooves recessedfrom the second surface in the thickness direction. The firstredistribution parts of the first conductors are in contact with thefirst grooves.

A method of manufacturing a semiconductor device provided according to asecond aspect of the present disclosure comprises the steps of:embedding a semiconductor element having a plurality of electrodes onone side in a thickness direction into a sealing resin such that theelectrodes are exposed; forming an insulating layer laminated on thesealing resin and covering the electrodes; and forming a plurality ofconductors each having an embedded part and a redistribution part, withthe embedded part being embedded in the insulating layer and connectedto a relevant one of the electrodes, and with the redistribution partbeing disposed on the insulating layer and connected to the embeddedpart. The insulating layer is made of a material containing athermosetting synthetic resin and an additive that contains a metallicelement forming portions of the conductors. The step of forming aplurality of conductors includes: forming with a laser in the insulatinglayer a plurality of holes that expose the electrodes and a plurality ofgrooves recessed from a surface of the insulating layer and connected tothe holes to thereby deposit a base layer that covers wall surfacesdefining the holes and the grooves; and forming a plating layer coveringthe base layer.

Other features and advantages of the present disclosure will becomeclearer from the detailed description given below with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a semiconductor device according to a firstembodiment of the present disclosure, as seen through a sealing resin;

FIG. 2 is a plan view corresponding to FIG. 1, in which a semiconductorelement is illustrated as transparent;

FIG. 3 is a bottom view of the semiconductor device shown in FIG. 1;

FIG. 4 is a bottom view corresponding to FIG. 3, as seen through aprotective layer and a plurality of terminals.

FIG. 5 is a sectional view taken along line V-V in FIG. 1;

FIG. 6 is a sectional view taken along line VI-VI in FIG. 1;

FIG. 7 is a partial enlarged view of FIG. 5;

FIG. 8 is a partial enlarged view of FIG. 5;

FIG. 9 is a partial enlarged sectional view taken along line IX-IX inFIG. 1;

FIG. 10 is a sectional view illustrating a step of a manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 11 is a sectional view illustrating a step of the manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 12 is a sectional view illustrating a step of the manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 13 is a partial enlarged view of FIG. 12;

FIG. 14 is a sectional view illustrating a step of the manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 15 is a partial enlarged view of FIG. 14;

FIG. 16 is a sectional view illustrating a step of the manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 17 is a sectional view illustrating a step of the manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 18 is a sectional view illustrating a step of the manufacturingmethod for the semiconductor device shown in FIG. 1;

FIG. 19 is a plan view of a semiconductor device according to a secondembodiment of the present disclosure, as seen through a sealing resin;

FIG. 20 is a plan view corresponding to FIG. 19, in which a firstinsulating layer and a semiconductor element are illustrated astransparent;

FIG. 21 is a bottom view of the semiconductor device shown in FIG. 19;

FIG. 22 is a bottom view corresponding to FIG. 21, as seen through aprotective layer and a plurality of terminals;

FIG. 23 is a sectional view taken along line XXIII-XXIII in FIG. 20;

FIG. 24 is a sectional view taken along line XXIV-XXIV in FIG. 20;

FIG. 25 is a partial enlarged view of FIG. 23;

FIG. 26 is a partial enlarged sectional view taken along line XXVI-XXVIin FIG. 20;

FIG. 27 is a plan view of a semiconductor device according to a thirdembodiment of the present disclosure, as seen through a heat dissipator,a bonding layer and a sealing resin;

FIG. 28 is a bottom view of the semiconductor device shown in FIG. 27;

FIG. 29 is a bottom view corresponding to FIG. 28, as seen through afirst insulating layer, a protective layer and a plurality of terminals;

FIG. 30 is a sectional view taken along line XXX-XXX in FIG. 27;

FIG. 31 is a sectional view taken along line XXXI-XXXI in FIG. 27;

FIG. 32 is a partial enlarged view of FIG. 30;

FIG. 33 is a plan view of a semiconductor device according to a fourthembodiment of the present disclosure, as seen through a sealing resin;

FIG. 34 is a plan view corresponding to FIG. 33, in which a firstinsulating layer and a plurality of first conductors are illustrated astransparent; and

FIG. 35 is a sectional view taken along line XXXV-XXXV in FIG. 33;

MODE FOR CARRYING OUT THE INVENTION

Modes for carrying out the present disclosure are described below withreference to the accompanying drawings.

First Embodiment

A semiconductor device A10 according to a first embodiment of thepresent disclosure is described below based on FIGS. 1-9. Thesemiconductor device A10 includes a first insulating layer 11, aplurality of first conductors 21, a semiconductor element 30, a sealingresin 41, a protective layer 42 and a plurality of terminals 50. Thesemiconductor device A10 is of a Fan-Out package type to besurface-mounted on a wiring board. In FIG. 1, the sealing resin 41 isillustrated as transparent for convenience of understanding. FIG. 2corresponds to FIG. 1, but the semiconductor element 30 is alsoillustrated as transparent for convenience of understanding. In FIG. 4,the protective layer 42 and the terminals 50 are illustrated astransparent for convenience of understanding. In FIG. 2, the outline ofthe semiconductor element 30, which is illustrated as transparent, isshown by imaginary lines (double-dashed lines).

In the description of the semiconductor device A10, the thicknessdirection of the first insulating layer 11 is referred to as “thicknessdirection z”. A direction orthogonal to the thickness direction z isreferred to as “first direction x”. The direction orthogonal to both thethickness direction z and the first direction x is referred to as“second direction y”. As shown in FIG. 1, the outer shape of thesemiconductor device A10 is rectangular as viewed in the thicknessdirection z. The first direction x corresponds to the longitudinaldirection of the semiconductor device A10. The second direction ycorresponds to the widthwise direction of the semiconductor device A10.Note that the thickness direction z, the first direction x and thesecond direction y are applied to the description of the semiconductordevices A20-A40 described later.

As shown in FIGS. 5 and 6, the first insulating layer 11 faces thesemiconductor element 30 in the thickness direction z. The firstinsulating layer 11 is made of a material containing a thermosettingsynthetic resin and an additive that contains a metallic element formingportions of the first conductors 21. The synthetic resin may be an epoxyresin or a polyimide resin, for example. The first insulating layer 11has a first surface 11A, a second surface 11B and a plurality of endsurfaces 11C. The first surface 11A and the second surface 11B face awayfrom each other in the thickness direction z. The first surface 11Afaces the semiconductor element 30. In the semiconductor device A10,when the semiconductor device A10 is mounted on a wiring board, thesecond surface 11B faces the wiring board. The end surfaces 11C areconnected to both the first surface 11A and the second surface 11B. Eachof the end surfaces 11C faces either the first direction x or the seconddirection y.

As shown in FIGS. 7-9, the first insulating layer 11 has a plurality offirst grooves 111. The first grooves 111 are recessed from the secondsurface 11B in the thickness direction z. As shown in FIG. 9, the sidesurfaces of each of the first grooves 111 are flared in the thicknessdirection z from the bottom surface of the first groove 111 toward thesecond surface 11B. In each of the first grooves 111, the dimension c1of the bottom surface of the first groove 111 in the first direction xis smaller than the dimension c2 between the two boundaries between thefirst groove 111 and the second surface 11B, which are spaced apart fromeach other in the first direction x.

As shown in FIGS. 5 and 6, the first conductors 21 are disposed in thefirst insulating layer 11. The first conductors 21 form a conductionpath for supplying electric power to and inputting and outputtingsignals to and from the semiconductor element 30. Each of the firstconductors 21 has a first embedded part 211 and a first redistributionpart 212. At least a portion of each first embedded part 211 (theentirety in the semiconductor device A10) is embedded in the firstinsulating layer 11. As shown in FIG. 7, each first embedded part 211has a side surface that is flared in the thickness direction z from thefirst surface 11A toward the second surface 11B of the first insulatinglayer 11. The dimension b1 in the direction orthogonal to the thicknessdirection z of the end surface of the first embedded part 211 that isclosest to the first surface 11A is smaller than the dimension b2 in thedirection orthogonal to the thickness direction z of the end surface ofthe first embedded part 211 that is closest to the second surface 11B.The first redistribution parts 212 are disposed at the second surface11B of the first insulating layer 11. The first redistribution parts 212are connected to the first embedded parts 211. As shown in FIGS. 1-4, asviewed in thickness direction z, the first redistribution parts 212 ofthe first conductors 21 have portions located outside the semiconductorelement 30. The first redistribution parts 212 of the first conductors21 are in contact with the first grooves 111 of the first insulatinglayer 11. That is, portions of the first redistribution parts 212 of thefirst conductors 21 are embedded in the first grooves 111.

As shown in FIGS. 7 and 8, each of the first embedded parts 211 of thefirst conductors 21 and each of the first redistribution parts 212 ofthe first conductors 21 has a base layer 21A and a plating layer 21B.The base layers 21A are made of a metallic element contained in theadditive that is contained in the first insulating layer 11. The platinglayers 21B may be made of a material containing copper (Cu), forexample. The base layers 21A of the first embedded parts 211 are incontact with the first insulating layer 11. The plating layer 21B ofeach first embedded part 211 is surrounded by the base layer 21A of thefirst embedded part 211 around the thickness direction z. The base layer21A of each first redistribution part 212 is in contact with a relevantone of the first grooves 111 of the first insulating layer 11. Theplating layer 21B of each first redistribution part 212 covers the baselayer 21A of the first redistribution part 212. As shown in FIG. 9, theplating layer 21B of each first redistribution part 212 has a recess212A that is recessed in the thickness direction z. The recess 212Aextends along the direction in which the first redistribution part 212of the first conductor 21 extends.

As shown in FIGS. 5 and 6, the semiconductor element 30 is connected tothe first conductors 21. The semiconductor element 30 is in contact withthe first surface 11A of the first insulating layer 11. In thesemiconductor device A10, the semiconductor element 30 is an LSI (LargeScale Integration) that includes, for example, a voltage control circuitsuch as an LDO (Low Drop Out) or an amplifier circuit such as anoperational amplifier. In the semiconductor device A10, thesemiconductor element 30 is a flip-chip type element. As shown in FIGS.1, 5 and 6, the semiconductor element 30 has a plurality of electrodes31. The electrodes 31 are provided near the first surface 11A. Theelectrodes 31 are electrically connected to the circuit constructed inthe semiconductor element 30. The electrodes 31 may contain aluminum(Al), for example. The electrodes 31, some or all of them, may bedirectly connected to a corresponding number of the first embedded parts211 of the first conductors 21 (all are connected in the semiconductordevice A10). Thus, the semiconductor element 30 is electricallyconnected to the first conductors 21.

As shown in FIGS. 5 and 6, the sealing resin 41 covers a part of thesemiconductor element 30. The sealing resin 41 is in contact with thefirst surface 11A of the first insulating layer 11. The sealing resin 41may be made of a material containing a black epoxy resin, for example.The sealing resin 41 has a plurality of side surfaces 411. Each of theside surfaces 411 faces either the first direction x or the seconddirection y. Each of the side surfaces 411 is flush with one of the endsurfaces 11C of the first insulating layer 11.

As shown in FIGS. 5 and 6, the protective layer 42 is in contact withthe second surface 11B of the first insulating layer 11. The firstredistribution parts 212 of the first conductors 21 are covered with theprotective layer 42. The protective layer 42 is electrically insulating.The protective layer 42 may be made of a material containing polyimide,for example. As shown in FIGS. 3 and 8, the protective layer 42 has aplurality of openings 421. The openings penetrate the protective layer42 in the thickness direction z. Portions of the first redistributionparts 212 of the first conductors 21 are exposed through the openings421.

As shown in FIGS. 3 and 8, the terminals 50 are individually bonded tothe portions of the first redistribution parts 212 of the firstconductors 21 that are exposed through the openings 421 of theprotective layer 42. The terminals 50 are used for mounting thesemiconductor device A10 to a wiring board. The terminals 50 projectfrom the protective layer 42 in the thickness direction z. As shown inFIG. 8, in the example of the semiconductor device A10, each of theterminals 50 has a base part 51 and a bump part 52. Each base part 51 isin contact with a portion of a relevant one of the first redistributionparts 212 of the first conductors 21. The base part 51 is made up of aplurality of metal layers laminated in the order of a nickel (Ni) layer,a palladium (Pd) layer and a gold (Au) layer in the direction away fromthe second surface 11B of the first insulating layer 11 in the thicknessdirection z. Of these metal layers, a palladium layer may not beprovided. The bump part 52 is in contact with both of the base part 51and the protective layer 42. The bump part 52 includes a portionprojecting from the protective layer 42 in the thickness direction z.The bump part 52 is made of a material containing tin (Sn).

An example of a method of manufacturing the semiconductor device A10 isdescribed below with reference to FIGS. 11-18. Note that FIGS. 11-18(excluding FIGS. 13 and 15) are sectional views taken along the sameplane as FIG. 5.

First, a semiconductor element 30 is embedded into a sealing resin 81,as shown in FIG. 10. The sealing resin 81 is made of a materialcontaining a black epoxy resin. The semiconductor element 30 has aplurality of electrodes 31 on one side in the thickness direction z. Inthis step, after the material for the sealing resin 81 and thesemiconductor element 30 are placed in a mold, compression molding isperformed. In this way, the semiconductor element 30 is embedded intothe sealing resin 81. This step is performed such that the electrodes 31are exposed from the sealing resin 81.

Next, as shown in FIG. 11, an insulating layer 82 is laminated on thesealing resin 81 to cover the electrodes 31 of the semiconductor element30. The insulating layer 82 is made of a material containing athermosetting synthetic resin and an additive that contains a metallicelement that will form portions of conductors 83 (described later). Thesynthetic resin may be an epoxy resin or a polyimide resin, for example.The insulating layer 82 is formed by compression molding.

Next, as shown in FIGS. 12-15, a plurality of conductors 83 connectingto the electrodes 31 of the semiconductor element 30 are formed. Theconductors 83 correspond to the first conductors 21 of the semiconductordevice A10. As shown in FIG. 14, each of the conductors 83 has anembedded part 831 and a redistribution part 832. Each embedded part 831is embedded in the insulating layer 82 and connected to a relevant oneof the electrodes 31. The redistribution parts 832 are disposed on theinsulating layer 82 and connected to the embedded parts 831. As shown inFIG. 15, each of the embedded parts 831 of the conductors 83 and each ofthe redistribution parts 832 of the conductors 83 has a base layer 83Aand a plating layer 83B. The process of forming the conductors 83includes a step of depositing a base layer 83A covering the surface ofthe insulating layer 82 and a step of forming a plating layer 83B thatcovers the base layer 83A.

First, as shown in FIG. 13, the base layer 83A covering the surface ofthe insulating layer 82 is deposited. In this step, as shown in FIG. 12,a plurality of holes 821 and a plurality of grooves 822 are formed inthe insulating layer 82 with a laser. The holes 821 penetrate theinsulating layer 82 in the thickness direction z. The electrodes 31 ofthe semiconductor element 30 are individually exposed through the holes821. The holes 821 are formed by irradiating the insulating layer 82with a laser beam until the electrodes 31 are exposed while monitoringthe positions of the electrodes 31 by image recognition using e.g. aninfrared camera. The laser irradiation position is corrected based onthe position information of the electrodes 31 obtained through imagerecognition. The grooves 822 are recessed from the surface of theinsulating layer 82 and connected to the holes 821. The grooves 822 areformed by irradiating the surface of the insulating layer 82 with alaser beam. The laser beam may be an ultraviolet laser beam having awavelength of 355 nm and a beam diameter of 17 μm, for example. As shownin FIG. 13, forming the holes 821 and the grooves 822 results indeposition of the base layer 83A that covers the wall surfaces definingthe holes 821 and the grooves 822. The base layer 83A is formed of ametallic element contained in the additive that is contained ininsulating layer 82. The metallic element contained in the additive isexcited by laser irradiation. As a result, a metal layer containing themetallic element is deposited as the base layer 83A.

Next, as shown in FIG. 15, a plating layer 83B covering the base layer83A is formed. The plating layer 83B is made of a material containingcopper. The plating layer 83B is formed by electroless plating. In thisway, an embedded part 831 is formed in each of the holes 821, as shownin FIG. 14. Also, a redistribution part 832 is formed in each of thegrooves 822. A plurality of conductors 83 are formed in this way.

Next, as shown in FIG. 16, a protective layer 84 is laminated on theinsulating layer 82 to cover portions of the conductors 83. Theprotective layer 84 has a plurality of openings 841 penetrating in thethickness direction z. Specifically, photosensitive polyimide is firstapplied to the surface of the insulating layer 82 and the surfaces ofthe conductors 83 using a spin coater. Then, photolithography patterningis performed to form openings 841 in the photosensitive polyimide. Inthis step, portions of the redistribution parts 832 of the conductors 83are exposed through the openings 841. The protective layer 84 is formedin this way.

Next, as shown in FIG. 17, a plurality of terminals 50 are formed thatare exposed through the openings 841 of the protective layer 84 andindividually bonded to the redistribution parts 832 of the conductors83. First, base parts 51 of the terminals 50 as shown in FIG. 8 areformed. The base parts 51B are formed by electroless plating. Next, bumpparts 52 of the terminals 50 as shown in FIG. 8 are formed. The bumpparts 52 are formed by melting a conductive material such as soldercontaining tin by reflowing and then solidifying by cooling. A pluralityof terminals 50 are formed in this way.

Finally, as shown in FIG. 18, the sealing resin 81, the insulating layer82 and the protective layer 84 are cut along the cutting lines CL withe.g. a dicing blade for division into a plurality of individual pieces.The cutting is performed such that each of the individual pieces includea single semiconductor element 30 and a plurality of conductors 83connected to the semiconductor element. The sealing resin 81, theinsulating layer and the protective layer 84 that are provided in eachindividual piece formed by this step correspond to the sealing resin 41,the first insulating layer 11 and the protective layer 42 of thesemiconductor device A10. By going through the above-described steps,the semiconductor device A10 is obtained.

The advantages of the semiconductor device A10 and the method ofmanufacturing the semiconductor device A10 are described below.

The semiconductor device A10 includes the first insulating layer 11having the second surface 11B, and first conductors 21 each having afirst embedded part 211 and a first redistribution part 212. The firstredistribution parts 212 of the first conductors 21 are disposed at thesecond surface 11B and connected to the first embedded parts 211 of thefirst conductors 21, which are connected to the electrodes 31 of thesemiconductor element 30. The first insulating layer 11 has a pluralityof first grooves 111 recessed from the second surface 11B in thethickness direction z. The first redistribution parts 212 of the firstconductors 21 are in contact with the first grooves 111. The firstgrooves 111 correspond to the grooves 822 formed in the insulating layer82 with a laser in the step of forming the conductors 83 in the methodof manufacturing the semiconductor device A10.

The process of forming the conductors 83 in the method of manufacturingthe semiconductor device A10 includes the step of depositing a baselayer 83A on the surface of the insulating layer 82 and the step offorming a plating layer 83B covering the base layer 83A. The conductors83 correspond to the first conductors 21 of the semiconductor deviceA10. The insulating layer 82 is made of a material containing athermosetting synthetic resin and an additive that contains a metallicelement that will form portions (i.e., the base layer 83A) of theconductors 83. In the step of depositing the base layer 83A, the holes821 and the grooves 822 are formed with a laser, which causes the baselayer 83A to be deposited on the wall surfaces defining the holes 821and the grooves 822. The holes 821 are formed to expose the electrodes31 of the semiconductor element 30 while monitoring the positions of theelectrodes 31 by image recognition. Thus, even when the semiconductorelement 30 has been displaced due to shrinkage of the sealing resin 81in curing, position correction corresponding to the displacement of theelectrodes 31 is performed through image recognition during the laserirradiation. Thus, the holes 821 can be formed precisely to expose theelectrodes 31. Accordingly, the conductors 83 can be formed precisely atthe positions of the electrodes 31. Thus, the semiconductor device A10and the method of manufacturing the semiconductor device A10 preventmisalignment between the electrodes 31 of the semiconductor element 30and the conductors 83 (the first conductors 21) at the joint portion.

In the step of forming the conductors 83 in the method of manufacturingthe semiconductor device A10, the plating layer 83B is formed byelectroless plating. Unlike the electroplating, this step does notrequire the deposition of the base layer 83A as a conduction path forplating, so that the conductors 83 can be formed efficiently.

Each of the first redistribution parts 212 of the first conductors 21has a base layer 21A in contact with a relevant one of the first grooves111 and a plating layer 21B covering the base layer 21A. Each platinglayer 21B has a recess 212A that is recessed in the thickness directionz. The recess 212A is a trace resulting from the step of forming theconductors 83 in the method of manufacturing the semiconductor deviceA10 as a result of forming the plating layer 83B on the base layer 83Acovering the grooves 822. Thus, each recess 212A extends along thedirection in which the relevant one of the first redistribution parts212 of the first conductors 21 extends.

The semiconductor device A10 further includes the protective layer 42 incontact with the second surface 11B of the first insulating layer 11 anda plurality of terminals 50. The terminals 50 are individually connectedto portions of the first redistribution parts 212 of the firstconductors 21 that are exposed through the openings 421 of theprotective layer 42. The terminals 50 project from the protective layer42 in the thickness direction z. The terminals 50 are made of a materialcontaining tin. Such a configuration facilitates the mounting of thesemiconductor device A10 to a wiring board.

Second Embodiment

A semiconductor device A20 according to a second embodiment of thepresent disclosure is described below with reference to FIGS. 19-26. Inthese figures, the elements that are the same as or similar to those ofthe semiconductor device A10 are denoted by the same reference signs asthose used for the semiconductor device A10, and the descriptionsthereof are omitted.

The semiconductor device A20 differs from the semiconductor device A10in that the semiconductor device A20 further includes a secondinsulating layer 12 and a plurality of second conductors 22 and inconfigurations of the protective layer 42 and the terminals 50. In FIG.19, the sealing resin 41 is illustrated as transparent for convenienceof understanding. FIG. 20 corresponds to FIG. 19, but the firstinsulating layer 11 and the semiconductor element 30 are alsoillustrated as transparent for convenience of understanding. In FIG. 22,the protective layer and the terminals 50 are illustrated as transparentfor convenience of understanding. In FIG. 20, the outline of thesemiconductor element 30, which is illustrated as transparent, is shownby imaginary lines.

As shown in FIGS. 23 and 24, the second insulating layer 12 is incontact with the second surface 11B of the first insulating layer 11.Thus, the first insulating layer 11 is sandwiched between the secondinsulating layer 12 and the sealing resin 41. The second insulatinglayer 12 is made of a material containing a thermosetting syntheticresin and an additive that contains a metallic element forming portionsof the second conductors 22. The synthetic resin may be an epoxy resinor a polyimide resin, for example. The second insulating layer 12 has athird surface 12A, a fourth surface 12B and a plurality of end surfaces12C. The third surface 12A and the fourth surface 12B face away fromeach other in the thickness direction z. The third surface 12A is incontact with the second surface 11B. When the semiconductor device A20is mounted on a wiring board, the fourth surface 12B faces the wiringboard. The end surfaces 12C are connected to both the third surface 12Aand the fourth surface 12B. Each of the end surfaces 12C faces eitherthe first direction x or the second direction y. Each of the endsurfaces 12C is flush with both of one of the end surfaces 11C of thefirst insulating layer 11 and one of the side surfaces 411 of thesealing resin 41.

As shown in FIGS. 25 and 26, the second insulating layer 12 has aplurality of second grooves 121. The second grooves 121 are recessedfrom the fourth surface 12B in the thickness direction z. As shown inFIG. 26, the side surfaces of each of the second grooves 121 are flaredin the thickness direction z from the bottom surface of the secondgroove 121 toward the fourth surface 12B. In each of the second grooves121, the dimension c3 of the bottom surface of the second groove 121 inthe first direction x is smaller than the dimension c4 between the twoboundaries between the second groove 121 and the fourth surface 12B,which are spaced apart from each other in the first direction x.

As shown in FIGS. 23 and 24, the second conductors 22 are disposed inthe second insulating layer 12. The second conductors 22, along with thefirst conductors 21, form a conduction path for the semiconductorelement 30. Each of the second conductors 22 has a second embedded part221 and a second redistribution part 222. The second embedded parts 221are embedded in the second insulating layer 12. As shown in FIG. 25,each second embedded part 221 has a side surface that is flared in thethickness direction z from the third surface 12A toward the fourthsurface 12B of the second insulating layer 12. The dimension b3 in thedirection orthogonal to the thickness direction z of the end surface ofthe second embedded part 221 that is closest to the third surface 12A issmaller than the dimension b4 in the direction orthogonal to thethickness direction z of the end surface of the second embedded part 221that is closest to the fourth surface 12B. The second redistributionparts 222 are disposed at the fourth surface 12B of the secondinsulating layer 12. The second redistribution parts 222 are connectedto the first redistribution parts 212. The second redistribution parts222 of the second conductors 22 are in contact with the second grooves121 of the second insulating layer 12. That is, portions of the secondredistribution parts 222 of the second conductors 22 are embedded in thesecond grooves 121.

As shown in FIGS. 23 and 24, the second embedded parts 221 of the secondconductors 22 are connected to the first redistribution parts 212 of thefirst conductors 21. Thus, the semiconductor element 30 is electricallyconnected to the second conductors 22 via the first conductors 21. Thesecond redistribution parts 221 of the second conductors 22 are coveredwith the second insulating layer 12. As shown in FIGS. 20 and 22, asviewed in the thickness direction z, the second redistribution parts 222of the second conductors 22 include portions that overlap with the firstredistribution parts 212 of the first conductors 21.

As shown in FIG. 25, each of the second embedded parts 221 of the secondconductors 22 and each of the second redistribution parts 222 of thesecond conductors 22 has a base layer 22A and a plating layer 22B. Thebase layers 22A are made of a metallic element contained in the additivethat is contained in the second insulating layer 12. The plating layers22B may be made of a material containing copper, for example. The baselayers 22A of the second embedded parts 221 are in contact with thesecond insulating layer 12. The plating layer 22B of each secondembedded part 221 is surrounded by the base layer 22A of the secondembedded part 221 around the thickness direction z. The base layer 22Aof each second redistribution part 222 is in contact with a relevant oneof the second grooves 121 of the second insulating layer 12. The platinglayer 22B of each second redistribution part 222 covers the base layer22A of the second redistribution part 222. As shown in FIG. 26, theplating layer 22B of each second redistribution part 222 has a recess222A that is recessed in the thickness direction z. The recess 222Aextends along the direction in which the second redistribution part 222of the second conductor 22 extends.

As shown in FIGS. 23 and 24, the protective layer 42 is in contact withthe fourth surface 12B of the second insulating layer 12. The secondredistribution parts 222 of the second conductors 22 are covered withthe protective layer 42. Portions of the second redistribution parts 222of the second conductors 22 are exposed through the openings 421 of theprotective layer 42. As shown in FIGS. 21 and 25, the terminals 50 areindividually bonded to the portions of the second redistribution parts222 of the second conductors 22 that are exposed through the openings421.

The advantages of the semiconductor device A20 are described below.

The semiconductor device A20 includes the first insulating layer 11having the second surface 11B, and first conductors 21 each having afirst embedded part 211 and a first redistribution part 212. The firstredistribution parts 212 of the first conductors 21 are disposed at thesecond surface 11B and connected to the first embedded parts 211 of thefirst conductors 21, which are connected to the electrodes 31 of thesemiconductor element 30. The first insulating layer 11 has a pluralityof first grooves 111 recessed from the second surface 11B in thethickness direction z. The first redistribution parts 212 of the firstconductors 21 are in contact with the first grooves 111. Thus, thesemiconductor device A20 also prevents misalignment between theelectrodes 31 of the semiconductor element 30 and the first conductors21 at the joint portion.

The semiconductor device A20 further includes the second insulatinglayer 12 having the third surface 12A and the fourth surface 12B, andsecond conductors 22 each having a second embedded part 221 and a secondredistribution part 222. The third surface 12A is in contact with thesecond surface 11B of the first insulating layer 11. The secondredistribution parts 222 of the second conductors 22 are disposed at thefourth surface 12B and connected to the second embedded parts 221 of thesecond conductors 22 that are embedded in the second insulating layer12. The first redistribution parts 212 of the first conductors 21 areconnected to the second embedded parts 221 of the second conductors 22and covered with the second insulating layer 12. Thus, in thesemiconductor device A20, the first conductors 21 and the secondconductors 22 are stacked in the thickness direction z. Thus, as viewedin the thickness direction z, the second redistribution parts 222 of thesecond conductors 22 overlap with the first redistribution parts 212 ofthe first conductors 21. In this way, the semiconductor device A20realizes a more complicated wiring pattern than that of thesemiconductor device A10.

Third Embodiment

A semiconductor device A30 according to a third embodiment of thepresent disclosure is described below with reference to FIGS. 27-32. Inthese figures, the elements that are the same as or similar to those ofthe semiconductor device A10 are denoted by the same reference signs asthose used for the semiconductor device A10, and the descriptionsthereof are omitted.

The semiconductor device A30 differs from the semiconductor device A10in that the semiconductor device A30 further includes a heat dissipator23 and a bonding layer 39 and in configurations of the first embeddedparts 211 of the first conductors 21 and the semiconductor element 30.In FIG. 27, the heat dissipator 23, the bonding layer 39 and the sealingresin 41 are illustrated as transparent for convenience ofunderstanding. In FIG. 29, the first insulating layer 11, the protectivelayer 42 and the terminals 50 are illustrated as transparent forconvenience of understanding. In FIG. 27, the respective outlines of theheat dissipator 23 and the bonding layer 39, which are illustrated astransparent, are shown by imaginary lines.

In the semiconductor device A30, the semiconductor element is aswitching element such as a MOSFET (Metal-Oxide-SemiconductorField-Effect Transistor). Thus, the semiconductor device A30 can be usedfor e.g. DC/DC converters or inverters of various electric appliances.

As shown in FIGS. 30 and 31, the heat dissipator 23 is located on theopposite side of the first insulating layer 11 with respect to thesemiconductor element 30 in the thickness direction z. At least aportion of the heat dissipator 23 is covered with the sealing resin 41.The heat dissipator 23 is a metal plate containing copper, for example.The heat dissipator 23 dissipates the heat generated from thesemiconductor element 30 during the use of the semiconductor device A30and also forms a conduction path for the semiconductor element 30, alongwith the first conductors 21.

In the semiconductor device A30, the semiconductor element 30 may be aMOSFET made from a semiconductor material mainly composed of siliconcarbide (SiC), for example. The semiconductor element 30 is not limitedto a MOSFET and may be a field effect transistor including a MISFET(Metal-Insulator-Semiconductor Field-Effect Transistor) or a bipolartransistor such as an IGBT (Insulated Gate Bipolar Transistor). In thedescription of the semiconductor device A30, it is assumed that thesemiconductor element 30 is an N-channel MOSFET.

As shown in FIGS. 27 and 29-32, the electrodes 31 of the semiconductorelement 30 include a front surface electrode 311 and a gate electrode312. As viewed in the thickness direction z, the area of the frontsurface electrode 311 is larger than that of the gate electrode 312. Tothe front surface electrode 311, a source current flows from inside thesemiconductor element 30. To the gate electrode 312, a gate voltage fordriving the semiconductor element 30 is applied.

As shown in FIG. 32, the semiconductor element 30 has a back surfaceelectrode 32 and an insulating film 33. As shown in FIGS. 30-32, theback surface electrode 32 is located farther from the first surface 11Aof the first insulating layer 11 than are the front surface electrode311 and the gate electrode 312. The back surface electrode 32 faces theheat dissipator 23. The back surface electrode 32 is provided on theentirety of the surface of the semiconductor element 30 that faces theheat dissipator 23. A drain current flows through the back surfaceelectrode 32 toward the inside of the semiconductor element 30.

As shown in FIG. 32, as with the front surface electrode 311 and thegate electrode 312, the insulating film 33 is provided near the firstsurface 11A of the first insulating layer 11. As shown in FIG. 29, asviewed in the thickness direction z, the insulating film 33 surroundseach of the front surface electrode 311 and the gate electrode 312. Theinsulating film 33 may be provided by laminating layers in the order ofa silicon dioxide (SiO₂) layer, a silicon nitride (Si₃N₄) layer and apolybenzoxazole (PBO) layer in the direction toward the first surface11A in the thickness direction z. The insulating film 33 may include apolyimide layer instead of a polybenzoxazole layer.

As shown in FIGS. 30-32, the bonding layer 39 is interposed between theback surface electrode 32 of the semiconductor element 30 and the heatdissipator 23. The bonding layer 39 may be lead-free solder mainlycomposed of tin or baked silver, for example. Thus, the back surfaceelectrode 32 is bonded to the heat dissipator 23. The heat dissipator 23is electrically connected to the back surface electrode 32 via thebonding layer 39.

As shown in FIG. 30, some of the first embedded parts 211 of the firstconductors 21 are embedded in the first insulating layer 11, whileothers are embedded in both the first insulating layer 11 and thesealing resin 41. The first embedded parts 211 of the first conductors21 that are embedded in the first insulating layer 11 are connected tothe electrodes 31 (the front surface electrode 311 and the gateelectrode 312) of the semiconductor element 30. The first embedded parts211 of the first conductors 21 that are embedded in both the firstinsulating layer 11 and the sealing resin 41 are bonded to the heatdissipator 23.

The advantages of the semiconductor device A30 are described below.

The semiconductor device A30 includes the first insulating layer 11having the second surface 11B, and first conductors 21 each having afirst embedded part 211 and a first redistribution part 212. The firstredistribution parts 212 of the first conductors 21 are disposed at thesecond surface 11B and connected to the first embedded parts 211 of thefirst conductors 21, which are connected to the electrodes 31 of thesemiconductor element 30. The first insulating layer 11 has a pluralityof first grooves 111 recessed from the second surface 11B in thethickness direction z. The first redistribution parts 212 of the firstconductors 21 are in contact with the first grooves 111. Thus, thesemiconductor device A30 also prevents misalignment between theelectrodes 31 of the semiconductor element 30 and the first conductors21 at the joint portion.

The semiconductor device A30 further includes the heat dissipator 23located on the opposite side of the first insulating layer 11 withrespect to the semiconductor element 30. The back surface electrode 32of the semiconductor element 30 and some of the first embedded parts 211of the first conductors 21 are bonded to the heat dissipator 23. Withsuch an arrangement, when the semiconductor element 30 is an N-channelMOSFET, the heat dissipator 23 forms a conduction path of thesemiconductor element 30 for the drain current to flow. Also, during theuse of the semiconductor device A30, the heat generated from thesemiconductor element 30 is efficiently dissipated to the outside.

Fourth Embodiment

A semiconductor device A40 according to a fourth embodiment of thepresent disclosure is described below with reference to FIGS. 33-35. Inthese figures, the elements that are the same as or similar to those ofthe semiconductor device A10 are denoted by the same reference signs asthose used for the semiconductor device A10, and the descriptionsthereof are omitted.

The semiconductor device A40 differs from the semiconductor device A10in that the semiconductor device A40 further includes a plurality ofthrough conductors 24 and a light-transmitting resin 43 and inconfigurations of the semiconductor element 30 and the terminals 50. Thesemiconductor device A40 is not provided with the protective layer 42.In FIG. 33, the light-transmitting resin 43 is illustrated astransparent for convenience of understanding. FIG. 34 corresponds toFIG. 33, but the first insulating layer 11 and the first conductors 21are also illustrated as transparent for convenience of understanding. InFIG. 34, the outline of the first insulating layer 11, which isillustrated as transparent, is shown by imaginary lines.

As shown in FIGS. 33-35, the first insulating layer 11 includes portionsspaced apart from each other in the first direction x. Thus, thesemiconductor element 30 includes a portion that is not covered with thefirst insulating layer 11. The semiconductor element 30 of thesemiconductor device A40 is an optical element configured to emit lightfrom this portion. In the example of the semiconductor device A40, theoptical element is an LED. When a voltage is applied to the electrodes31 of the semiconductor element 30, light is emitted from theabove-mentioned portion in the thickness direction z.

As shown in FIGS. 33 and 34, the through conductors 24 are locatedoutside the semiconductor element 30 as viewed in the thicknessdirection z. As shown in FIG. 35, the through conductors 24 areconnected to the first redistribution parts 212 of the first conductors21. The through conductors 24 extend from the first redistribution parts212 of the first conductors 21 in the thickness direction z andpenetrate the sealing resin 41. The through conductors 24 are made of amaterial containing copper, for example.

As shown in FIG. 35, the light-transmitting resin 43 is in contact withthe sealing resin 41. The light-transmitting resin 43 covers respectiveportions of the first insulating layer 11, semiconductor element 30 andfirst redistribution parts 212 of the first conductor 21. The lightemitted from the semiconductor element 30 passes through thelight-transmitting resin 43. The light-transmitting resin 43 is made ofa material containing a transparent epoxy resin or a synthetic resincontaining silicone.

As shown in FIG. 35, the terminals 50 are individually connected to theportions of the through conductors 24 that are exposed from the sealingresin 41. The terminals 50 project from the sealing resin 41 in thethickness direction z.

The advantages of the semiconductor device A40 are described below.

The semiconductor device A40 includes the first insulating layer 11having the second surface 11B, and first conductors 21 each having afirst embedded part 211 and a first redistribution part 212. The firstredistribution parts 212 of the first conductors 21 are disposed at thesecond surface 11B and connected to the first embedded parts 211 of thefirst conductors 21, which are connected to the electrodes 31 of thesemiconductor element 30. The first insulating layer 11 has a pluralityof first grooves 111 recessed from the second surface 11B in thethickness direction z. The first redistribution parts 212 of the firstconductors 21 are in contact with the first grooves 111. Thus, thesemiconductor device A40 also prevents misalignment between theelectrodes 31 of the semiconductor element 30 and the first conductors21 at the joint portion.

In the semiconductor device A40, the semiconductor element 30 is anoptical element configured to emit light from the portion that is notcovered with the first insulating layer 11. The semiconductor device A40further includes through conductors 24 located outside the semiconductorelement 30 as viewed in the thickness direction z and connected to thefirst redistribution parts 212 of the first conductors 21. The throughconductors 24 extend from the first redistribution parts 212 of thefirst conductors 21 in the thickness direction z and penetrate thesealing resin 41. Such an arrangement allows the semiconductor deviceA40 to be mounted on a wiring bord such that the side opposite the lightemission side of the semiconductor element 30 in the thickness directionz faces the wiring board.

The present disclosure is not limited to the foregoing embodiments. Forexample, although all the foregoing embodiments have a singlesemiconductor element 30, a plurality of semiconductor elements may beprovided. Also, all the semiconductor devices according to the foregoingembodiments have an outer shape that is rectangular as viewed in thethickness direction z, but the outer shape is not limited to arectangular shape and may be a circular or a hexagonal shape. Thespecific configuration of each part of the present disclosure may bevaried in design in many ways.

Various embodiments of the present disclosure are defined in thefollowing clauses.

Clause 1.

A semiconductor device comprising:

a first insulating layer having a first surface and a second surfacefacing away from each other in a thickness direction;

a plurality of first conductors each having a first embedded part and afirst redistribution part, at least a portion of the first embedded partbeing embedded in the first insulating layer, the first redistributionpart being disposed at the second surface and connected to the firstembedded part;

a semiconductor element that is in contact with the first surface andhas a plurality of electrodes, the electrodes being provided near thefirst surface and connected to at least a predetermined number of thefirst embedded parts of the first conductors; and

a sealing resin that is in contact with the first surface and covers aportion of the semiconductor element;

wherein the first redistribution parts of the first conductors includeportions located outside the semiconductor element as viewed in thethickness direction,

the first insulating layer has a plurality of first grooves recessedfrom the second surface in the thickness direction, and

the first redistribution parts of the first conductors are in contactwith the first grooves.

Clause 2.

The semiconductor device according to clause 1, wherein the firstinsulating layer is made of a material containing a thermosettingsynthetic resin and an additive that contains a metallic element formingportions of the first conductors.

Clause 3.

The semiconductor device according to clause 2, wherein each of thefirst redistribution parts of the first conductors has a base layer thatis in contact with a relevant one of the first grooves and a platinglayer covering the base layer,

the base layer is formed of the metallic element contained in theadditive, and

the plating layer has a recess that is recessed in the thicknessdirection.

Clause 4.

The semiconductor device according to clause 3, wherein the recessextends along a direction in which a relevant one of the firstredistribution parts of the first conductors extends.

Clause 5.

The semiconductor device according to clause 4, further comprising aprotective layer that is in contact with the second surface,

wherein the protective layer has a plurality of openings penetrating inthe thickness direction, and

portions of the first redistribution parts of the first conductors areexposed through the openings.

Clause 6.

The semiconductor device according to clause 5, further comprising aplurality of terminals,

wherein the terminals are individually bonded to the portions of thefirst redistribution parts of the first conductors that are exposedthrough the openings, and

the terminals project from the protective layer in the thicknessdirection.

Clause 7.

The semiconductor device according to clause 6, wherein the terminalsare made of a material containing tin.

Clause 8.

The semiconductor device according to any one of clauses 1-4, furthercomprising: a second insulating layer having a third surface and afourth surface facing away from each other in a thickness direction, thethird surface being in contact with the second surface; and

a plurality of second conductors each having a second embedded part anda second redistribution part, the second embedded part being embedded inthe second insulating layer, the second redistribution part beingdisposed at the fourth surface and connected to the second embeddedpart,

wherein the first redistribution parts of the first conductors areconnected to the second embedded parts of the second conductors andcovered with the second insulating layer.

Clause 9.

The semiconductor device according to clause 8, wherein the secondredistribution parts of the second conductors include portions thatoverlap with the first redistribution parts of the first conductors asviewed in the thickness direction.

Clause 10.

The semiconductor device according to clause 9, wherein the secondinsulating layer has a plurality of second grooves recessed from thefourth surface in the thickness direction, and the second redistributionparts of the second conductors are in contact with the second grooves.

Clause 11.

The semiconductor device according to clause 10, wherein the secondinsulating layer is made of a material containing a thermosettingsynthetic resin and an additive that contains a metallic element formingportions of the second conductors.

Clause 12.

The semiconductor device according to any one of clauses 1-11, furthercomprising a heat dissipator located on an opposite side of the firstinsulating layer with respect to the semiconductor element,

wherein the electrodes include a front surface electrode and a gateelectrode,

the semiconductor element has a back surface electrode located fartherfrom the first surface than are the front surface electrode and the gateelectrode in the thickness direction,

the back surface electrode and selected ones of the first embedded partsof the first conductors are bonded to the heat dissipator, and

at least a portion of the heat dissipator is covered with the sealingresin.

Clause 13.

The semiconductor device according to any one of clauses 1-4, whereinthe semiconductor element is an optical element configured to emit lightfrom a portion thereof that is not covered with the first insulatinglayer,

the semiconductor device further comprises a plurality of throughconductors located outside the semiconductor element as viewed in thethickness direction and connected to the first redistribution parts ofthe first conductors, and

the through conductors extend from the first redistribution parts of thefirst conductors in the thickness direction and penetrate the sealingresin.

Clause 14.

The semiconductor device according to clause 13 further comprising alight-transmitting resin that is in contact with the sealing resin,

wherein the light-transmitting resin covers a portion of the firstinsulating layer, a portion of the semiconductor element, and portionsof the first redistribution parts of the first conductors.

Clause 15.

The semiconductor device according to clause 13 or 14, furthercomprising a plurality of terminals,

wherein the terminals are bonded to portions of the through conductorsthat are exposed from the sealing resin, and

the terminals project from the sealing resin in the thickness direction.

Clause 16.

A method of manufacturing a semiconductor device comprising the stepsof:

embedding a semiconductor element having a plurality of electrodes onone side in a thickness direction into a sealing resin such that theelectrodes are exposed;

forming an insulating layer laminated on the sealing resin and coveringthe electrodes; and

forming a plurality of conductors each having an embedded part and aredistribution part, the embedded part being embedded in the insulatinglayer and connected to a relevant one of the electrodes, theredistribution part being disposed on the insulating layer and connectedto the embedded part,

wherein the insulating layer is made of a material containing athermosetting synthetic resin and an additive that contains a metallicelement forming portions of the conductors, and

the step of forming a plurality of conductors includes: forming with alaser in the insulating layer a plurality of holes that expose theelectrodes and a plurality of grooves recessed from a surface of theinsulating layer and connected to the holes to thereby deposit a baselayer that covers wall surfaces defining the holes and the grooves; andforming a plating layer covering the base layer.

Clause 17.

The method of manufacturing a semiconductor device according to clause16, wherein the step of forming the plating layer comprises forming theplating layer by electroless plating.

1. A semiconductor device comprising: a first insulating layer having afirst surface and a second surface facing away from each other in athickness direction; a plurality of first conductors each having a firstembedded part and a first redistribution part, at least a portion of thefirst embedded part being embedded in the first insulating layer, thefirst redistribution part being disposed at the second surface andconnected to the first embedded part; a semiconductor element that is incontact with the first surface and has a plurality of electrodes, theelectrodes being provided near the first surface and connected to atleast a predetermined number of the first embedded parts of the firstconductors; and a sealing resin that is in contact with the firstsurface and covers a portion of the semiconductor element; wherein thefirst redistribution parts of the first conductors include portionslocated outside the semiconductor element as viewed in the thicknessdirection, the first insulating layer has a plurality of first groovesrecessed from the second surface in the thickness direction, and thefirst redistribution parts of the first conductors are in contact withthe first grooves.
 2. The semiconductor device according to claim 1,wherein the first insulating layer is made of a material containing athermosetting synthetic resin and an additive that contains a metallicelement forming portions of the first conductors.
 3. The semiconductordevice according to claim 2, wherein each of the first redistributionparts of the first conductors has a base layer that is in contact with arelevant one of the first grooves and a plating layer covering the baselayer, the base layer is formed of the metallic element contained in theadditive, and the plating layer has a recess that is recessed in thethickness direction.
 4. The semiconductor device according to claim 3,wherein the recess extends along a direction in which a relevant one ofthe first redistribution parts of the first conductors extends.
 5. Thesemiconductor device according to claim 4, further comprising aprotective layer that is in contact with the second surface, wherein theprotective layer has a plurality of openings penetrating in thethickness direction, and portions of the first redistribution parts ofthe first conductors are exposed through the openings.
 6. Thesemiconductor device according to claim 5, further comprising aplurality of terminals, wherein the terminals are individually bonded tothe portions of the first redistribution parts of the first conductorsthat are exposed through the openings, and the terminals project fromthe protective layer in the thickness direction.
 7. The semiconductordevice according to claim 6, wherein the terminals are made of amaterial containing tin.
 8. The semiconductor device according to claim1, further comprising: a second insulating layer having a third surfaceand a fourth surface facing away from each other in a thicknessdirection, the third surface being in contact with the second surface;and a plurality of second conductors each having a second embedded partand a second redistribution part, the second embedded part beingembedded in the second insulating layer, the second redistribution partbeing disposed at the fourth surface and connected to the secondembedded part, wherein the first redistribution parts of the firstconductors are connected to the second embedded parts of the secondconductors and covered with the second insulating layer.
 9. Thesemiconductor device according to claim 8, wherein the secondredistribution parts of the second conductors include portions thatoverlap with the first redistribution parts of the first conductors asviewed in the thickness direction.
 10. The semiconductor deviceaccording to claim 9, wherein the second insulating layer has aplurality of second grooves recessed from the fourth surface in thethickness direction, and the second redistribution parts of the secondconductors are in contact with the second grooves.
 11. The semiconductordevice according to claim 10, wherein the second insulating layer ismade of a material containing a thermosetting synthetic resin and anadditive that contains a metallic element forming portions of the secondconductors.
 12. The semiconductor device according to claim 1, furthercomprising a heat dissipator located on an opposite side of the firstinsulating layer with respect to the semiconductor element, wherein theelectrodes include a front surface electrode and a gate electrode, thesemiconductor element has a back surface electrode located farther fromthe first surface than are the front surface electrode and the gateelectrode in the thickness direction, the back surface electrode andselected ones of the first embedded parts of the first conductors arebonded to the heat dissipator, and at least a portion of the heatdissipator is covered with the sealing resin.
 13. The semiconductordevice according to claim 1, wherein the semiconductor element is anoptical element configured to emit light from a portion thereof that isnot covered with the first insulating layer, the semiconductor devicefurther comprises a plurality of through conductors located outside thesemiconductor element as viewed in the thickness direction and connectedto the first redistribution parts of the first conductors, and thethrough conductors extend from the first redistribution parts of thefirst conductors in the thickness direction and penetrate the sealingresin.
 14. The semiconductor device according to claim 13 furthercomprising a light-transmitting resin that is in contact with thesealing resin, wherein the light-transmitting resin covers a portion ofthe first insulating layer, a portion of the semiconductor element, andportions of the first redistribution parts of the first conductors. 15.The semiconductor device according to claim 13, further comprising aplurality of terminals, wherein the terminals are bonded to portions ofthe through conductors that are exposed from the sealing resin, and theterminals project from the sealing resin in the thickness direction. 16.A method of manufacturing a semiconductor device comprising the stepsof: embedding a semiconductor element having a plurality of electrodeson one side in a thickness direction into a sealing resin such that theelectrodes are exposed; forming an insulating layer laminated on thesealing resin and covering the electrodes; and forming a plurality ofconductors each having an embedded part and a redistribution part, theembedded part being embedded in the insulating layer and connected to arelevant one of the electrodes, the redistribution part being disposedon the insulating layer and connected to the embedded part, wherein theinsulating layer is made of a material containing a thermosettingsynthetic resin and an additive that contains a metallic element formingportions of the conductors, and the step of forming a plurality ofconductors includes: forming with a laser in the insulating layer aplurality of holes that expose the electrodes and a plurality of groovesrecessed from a surface of the insulating layer and connected to theholes to thereby deposit a base layer that covers wall surfaces of theholes and the grooves; and forming a plating layer covering the baselayer.
 17. The method of manufacturing a semiconductor device accordingto claim 16, wherein the step of forming the plating layer comprisesforming the plating layer by electroless plating.